Spindle-releasing device for drilling machines



Feb. 5, 1929.v H. SAUVEUR SPINDLE RELIEASINGA DEVICE FOR DRILLING MACHINES Filed Feb. 18, 1926 Patented Pet. s, 1929.

UNITED vSTATES HARRY SAUVEUR, 0F BERLIN', GERMANY, ASSIGNOB T0` FLEX-O-INDUS- rnIE-GEsELLscHAm', I. B.

H., 0F BERLIN, GERMANY.

SPDTDLE-REEASING DEVICE FOB BEIJING-MACHINES. i

npication led February 18, 1986, Serial lo. 89,120, and in Germanylarch 1, 1925*.

This invention relates-to spindle releasing devices for drilling machines, of the kind in which upon the permissible speed of'irota-A tionV being exceeded the drill. chuck is arranged to stop further rotation of the drill,

' and after such rotation has been stop ed the drill is set free to move in an axi direc-V tion, the forward or downward movement of the spindle thenremaining inoperative for a certain time so that the machine attendant has an opportunity to sto the machine bei fore the axial.. play of t e drill has been 'overtaken by' the downward movement of the rspindle.

Cases may -utilization of such opportunit isY not always possible, for example w en a workman has to attend to several drilling machines at the same time, or when the noise of the workshop is so` great or the lighting .conditions so unfavourable that the workman fails to notice an exceptional failure 'to act on-the part' of thel drill, and consequently injury may be done -to the the piece ofwork, or the drilling machlne.

The object of the present invention is to remove these -di1liculties,l and the invention consists in utilizing the axial displacement occurring upon the discontinuance of the relative rotation of the drill, forclosing an electric circuit by means of which the stoppage of the spindle thrust, or if necessary the complete stoppage of theV machine, can be .eifected According to this invention the, drill chuck is provided, at that part where space is-allowed for the axial displacement ofthe drill, with a unipolar oontactwhich is connected by means of an insulated lead' with an insulated contact ring surrounding thedrillchuck, which'ringmakes contact with la. pole o f the electric-circuit to cause the stoppage of the machine. i

The c used for pr ucing a-'signal of either an optical-or audible nature, or both. Referring to the drawing, wherein is disclosed a preferred embodiment of the in vention:

' Figure 1 is a side elevation of the ma- I chine with parte in section forpclearness of however occur where theV of the can also `bev inserted with its tapered shank b iny the spindle c, with the guide d of which `is connected one pole 12 of a circuit comprising the electric signal or stop motion. The clearance spaceg in the interior of the chuck permits axial displacement of the drill against the chuck. Within the clearance space gis located a contact device, which consists of the contact pin h, and the counter contact z' located in the chuck from which it is insulated; this counter. contact is conneoted by means of an insulated wire lc with the contact ring l insulatively mounted upon the chuck casing. The electrical connection of the contact ring Z with the `conductor'm is' effected by means of a disc n mounted in a rotatable 'and displaceable action, so that danger of injury to the drillV is avoided. From the be well understood, t at the object of the present invention is not the provision of an overload coupling for drill spindles, such overload couplings already existino` in many varieties of constructions, usually depending on the action of. sprin s. These are effective in hand operated dril s, where the workman will naturall cease to apply the power when he observes that disengagement has occurred, and they may also be quite suiiicient in machine .tools driven by otherthan manual power provided'the 'workman quickly stops the" application of the drive to the vdrill cluck, that is to say, before the'continued feedin of the drillhas over-runl the clear.- ance a owed by the disengaging mechanism; otherwie damage wouldvonly be deferred ha' theiation of the overload coupling'. In t. e provided for automatically bringing -about the discontinuance of the rotation of the drill spindle when excessivevresistance is encountered V"so that such dama e` is not only deferred but altogether avoidecjirrespective of prompt attention on the partpf the workman, and this advantage is l5tained in an foregoinv description, it will, y

resent invention, however, means are Cil extremely simple manner by utilizing the axial displacement which usually occurs upon the discontinuance of rotation of the drill to cut olf the supply of electrical power either from an individual drill spindle or if desirable, Jfrom the whole drilling machine in the case of a machine having a plurality l of drill spindles. Thev invention as described with reference to Figure 1 is ap licable to any overload coupling in the ac on of which such axial displacement takes place, but its application to yone construction of overload coupling taken as an exam le will be clear from the slightly more etailed drawings, Figures 1 and 2. This coupling comprises two tappets 1 and 1a adapted to pivot on pins 2 and having hooked ends 3.

normally registering in recesses in the tool holder 5 in the tapered bore of which the drill 7 is held in known manner. These tappets are pressed against the holder 5 by springs 8, the pressure 'of which springscan be adjusted in any known or suitable manner. The holder 5 is provided with a screw thread 9 working in an internal screw thread 10 formed in the chuck a. LWhen the resistance to the boring action ofthe drill becomes so great as to overpower the springs 8 and allow the holder 5 to disengage itself from the hooks 3, the holder screws itself upward inthe chuck until the pin It, of

/ the said holder meets the counter contact z',

and completes a circuit to lcause any suitable cut-out' switch to disconnect the drill spindle from the source of power Inthe example diagrammatically repre- 'sented in lFigure 1 the electrical lead 15a,

. visconnected with an ar1n26 fixed onl a' part 27 of the framework on which arm 26 is piv-` otedat 28 an larm 16 having a hook 18, and connected by a sprin 22 in tension with the said part 27 .l Anot er arm pivoted at 21 .carries at one end a hook 19, adapted to `engage the said hook 18, and at the other end an amature, 24. This arm 20 is normall through the parts d, c, b, a, 5,-, a, to the wire#` mi this wire m and the second wire 14 from the battery 11 then excite an electromagnet 25, which attracts the armature 24, extending the spring 23 and rocking 4the arm- 2() so that its hook 19 releases the hook .18 on the arm 16, whereupon the spring 22 contracts and moves the arm lo* away'from the contact piece on the lead '15h to open the motor circuit' and' allow the drill tocome to machine are too well known toneed illus'- tration. In the case of a drilling machine which is not eletricall driven ,the disengagement of a hook suc as the liook'18 described may cause or permit the action of l any suitable stop motion to occur.

r, s, t and u are insulations.

What I claim and desire Letters Patent of. the United States is l. In2 a vdrilling machine, a spindle, a chuck, a'drill adapted to be displaced axially in .relation to said chuck,'a contact member within said chuck, a secfond contact member partaking of such axial .movementsof said drill and adapted 'to engage the first named contact member, said contact members' formi-ng parts of an electrical circuit adapted when completed by such engage- `ment of said Contact members to bring about the stoppage of the forward movement of said spmdleand the actuation of a warning signal. l

2. In a drilling machine, a spindle, a chuck, a drill adapted to be displaced axially in relation to said chuck, a ring securedgoutside' said chuck, a contact member within said chuck electrically connected with said ring, a second contact member partaki'ng of to secure' by such axial movements of said drill and i adapted to engage the first named contact member, said contact members forming parts of an lelectrical circuit` adapted when completed by such engagement of said contact members to bring about the stoppage of the forward movement of said spindle.

3. In a drilling'machine, afspindle, a chuck, a drill. ada ted to be displaced axially in relation to sai v chuck, a ring secured outside said chuck, a rotatable and axially displaceable disc adapted to roll in contact with said ring, a contact member within said chuck electrically connected with said rin `asecond contact memberv partaking of suc axial movements of said drill and adapted to -engage' the irst named-contact member, said contact members, ring, and disc forming parts of an electrical circuit adapted when cmpleted to bring about the stoppage of the forward movement of said spindle.

4. In a drilling machine', a spindle, a chuck, a drill adapted to be displaced axially in relation lto said-chuck, a ring secured no M,

outside said chuck, a rotatable and axially displaceable disc adapted to roll in contact with said ring, a contact member within said chuck 'electrically connected, with said ring, a second lcontact member partaking of such axial Vmovements' of said4 drill and adapted to engage the first'named contact member, said contact members, wring, and

.disc forming part of .an electrical circuit adapted when completedto bring about the` v stoppage of the said machine. a standstill.v The motor andthe drillingv HARRY SAUVEUR. 

